8.4 무료쿠폰: 쿠폰 등록/재고/사용 처리/만료/1인 제한/로그 o

prisma/schema.prisma

@@ -220,6 +220,7 @@ model User {
   adminNotifications  AdminNotification[]  @relation("AdminNotificationCreator")
   ipBlocksCreated     IPBlock[]            @relation("IPBlockCreator")
   postViewLogs        PostViewLog[]        @relation("PostViewLogUser")
+  couponRedemptions   CouponRedemption[]
 
   @@index([status])
   @@index([createdAt])
@@ -583,3 +584,35 @@ model PasswordResetToken {
   @@index([userId, expiresAt])
   @@map("password_reset_tokens")
 }
+
+// 쿠폰
+model Coupon {
+  id          String   @id @default(cuid())
+  code        String   @unique
+  title       String
+  description String?
+  stock       Int      @default(0) // 총 재고
+  maxPerUser  Int      @default(1) // 1인당 제한
+  expiresAt   DateTime?
+  active      Boolean  @default(true)
+  createdAt   DateTime @default(now())
+
+  redemptions CouponRedemption[]
+
+  @@index([active, expiresAt])
+  @@map("coupons")
+}
+
+model CouponRedemption {
+  id        String   @id @default(cuid())
+  couponId  String
+  userId    String
+  createdAt DateTime @default(now())
+
+  coupon Coupon @relation(fields: [couponId], references: [id], onDelete: Cascade)
+  user   User   @relation(fields: [userId], references: [userId], onDelete: Cascade)
+
+  @@unique([couponId, userId])
+  @@index([userId, createdAt])
+  @@map("coupon_redemptions")
+}